Abstract: A device for providing electric power to a load, having two switch members (Z1, Z2) connected in series between positive and negative power supply rails. The first switch connected to the positive rail and the second switch connected to the negative rail, with an inductor (L) being connected to a bridge point between the switches and the load. Each switch having and a flywheel diode connected in parallel with a switchable member. A monitoring circuit monitors a current (I) through said inductor (L) and a bridge voltage (E) at said bridge point. A control circuit provides control signals to the switches for turning said switchable members ON and OFF. When said current is positive, the control circuit turns the first switch member OFF when said current exceeds a predetermined control value (I0) whereupon the current decreases towards zero and passes through the flywheel diode of the second switch member.

Abstract: A method and a device for operating a bridge power supply circuit comprising at least two switch members connected in series between two rails and operated alternatingly to provide a pulse width modulated output signal at a junction between the two transistors. A measurement circuit measures a voltage drop over the lower switch member during conduction of said switch member. The measurement is performed approximately in the middle of the ON-period and is used in the next cycle for calculating the timing signals. A control signal (Ucontrol) is received at an input for the pulse width modulated output signal. The measured voltage drop is added to the control signal before calculating the timing signals. The voltage drop is scaled by a scaling factor of for example 0.8 before being added to the control signal.

Abstract: A device for providing electric power to a load, having two switch members (Z1, Z2) connected in series between positive and negative power supply rails. The first switch connected to the positive rail and the second switch connected to the negative rail, with an inductor (L) being connected to a bridge point between the switches and the load. Each switch having and a flywheel diode connected in parallel with a switchable member. A monitoring circuit monitors a current (I) through said inductor (L) and a bridge voltage (E) at said bridge point. A control circuit provides control signals to the switches for turning said switchable members ON and OFF. When said current is positive, the control circuit turns the first switch member OFF when said current exceeds a predetermined control value (I0) whereupon the current decreases towards zero and passes through the flywheel diode of the second switch member.

Abstract: A process for producing high octane fuel from carbon dioxide and water is disclosed. The feedstock for the production line is industrial carbon dioxide and water, which may be of lower quality. The end product can be high octane gasoline, high cetane diesel or other liquid hydrocarbon mixtures suitable for driving conventional combustion engines or hydrocarbons suitable for further industrial processing or commercial use. Products, such as dimethyl ether or methanol may also be withdrawn from the production line. The process is emission free and reprocesses all hydrocarbons not suitable for liquid fuel to form high octane products. The heat generated by exothermic reactions in the process is fully utilizes as is the heat produced in the reprocessing of hydrocarbons not suitable for liquid fuel.

Abstract: A method and a device for operating a bridge power supply circuit comprising at least two switch members connected in series between two rails and operated alternatingly to provide a pulse width modulated output signal at a junction between the two transistors. A measurement circuit measures a voltage drop over the lower switch member during conduction of said switch member. The measurement is performed approximately in the middle of the ON-period and is used in the next cycle for calculating the timing signals. A control signal (Ucontrol) is received at an input for the pulse width modulated output signal. The measured voltage drop is added to the control signal before calculating the timing signals. The voltage drop is scaled by a scaling factor of for example 0.8 before being added to the control signal.

Abstract: In one embodiment a communication device activation system is provided to restore activation of one or more communication devices that are in a powered-down mode to conserve power usage during a period of inactivity. The activation signal, also referred to as a warm start signal, comprises a sequence signal. A sequence generator generates a desired sequence signal. It is contemplated that one or more sequence signals may be selected for use by the activation system. The sequence signal may be generated or stored and retrieved. To resume communication, a wake-up sequence signal is generated and transmitted to a remote communication device. Upon receipt the received signal is filtered, correlated and analyzed. Analysis may compare one or more aspects of the signal to a threshold signal. If the signal is determined to comprise a wake-up signal, i.e. a request for communication, then a warm-start operation may occur. An acknowledgement signal may optionally be generated to acknowledge receipt of the signal.

Abstract: The invention relates to a control means and method for a transistor switch circuit controlling a power supply circuit for providing electric power to a load, comprising: a power supply stage having an LC circuit with an inductor, and a control stage having an estimation of the inductor current as a feedback signal. According to the invention, the current through the inductor is measured by means of a measuring winding (17) and an integrator having the function of an RC network. The current measuring circuit is very stable and absolutely free from any source of offset signals. Also, it has no frequency limitations.

Abstract: The invention relates to a control means for a transistor switch circuit controlling a power supply circuit for providing electric power to a load, comprising: a power supply stage having a transistor bridge circuit and an LC circuit with an inductor and filter capacitors, and a control stage. The control stage comprises a monitor circuit for monitoring a bridge voltage of a connection between two semiconductor members and the current through the inductor, said monitor circuit comprising a first comparator for comparing when the current through the inductor exceeds a reference value and a second comparator for comparing when the bridge voltage changes polarity towards the corresponding rail polarity; and a drive circuit adapted to provide a firing pulse to one of said switchable members of said semiconductor members for initiating the conduction thereof.

Abstract: This invention relates to a multiple stage switch circuit for power electronics. The switch circuit is intended to supply electric power to any type of load. The invention provides a power supply circuit for providing power to a load, comprising: power supply stages each comprising a pair of switchable members in a bridge circuit and an LC filter connected between the center of the bridge circuit and the load, and a control stage for controlling turning on and off of the switchable members. According to the invention at least two power supply stages are connected in parallel with a common output to the load, and said power supply stages are synchronized by a common master control unit. The power supply circuit further comprises a unit for enabling a number of power supply stages while the rest of the power supply stages may be disabled in response to required output power characteristics.

Abstract: This invention relates to a multiple stage switch circuit for power electronics. The switch circuit is intended to supply electric power to any type of load. The invention provides a power supply circuit for providing power to a load, comprising: power supply stages each comprising a pair of switchable members in a bridge circuit and an LC filter connected between the centre of the bridge circuit and the load, and a control stage for controlling turning on and off of the switchable members. According to the invention at least two power supply stages are connected in parallel with a common output to the load, and said power supply stages are synchronised by a common master control unit. The power supply circuit further comprises a unit for enabling a number of power supply stages while the rest of the power supply stages may be disabled in response to required output power characteristics.

Abstract: The invention relates to a control means for a transistor switch circuit controlling a power supply circuit for providing electric power to a load, comprising: a power supply stage having a transistor bridge circuit and an LC circuit with an inductor and filter capacitors, and a control stage. The control stage comprises a monitor circuit for monitoring a bridge voltage of a connection between two semiconductor members and the current through the inductor, said monitor circuit comprising a first comparator for comparing when the current through the inductor exceeds a reference value and a second comparator for comparing when the bridge voltage changes polarity towards the corresponding rail polarity; and a drive circuit adapted to provide a firing pulse to one of said switchable members of said semiconductor members for initiating the conduction thereof.

Abstract: The invention relates to a control means and method for a transistor switch circuit controlling a power supply circuit for providing electric power to a load, comprising: a power supply stage having an LC circuit with an inductor, and a control stage having an estimation of the inductor current as a feedback signal. According to the invention, the current through the inductor is measured by means of a measuring winding (17) and an integrator having the function of an RC network. The current measuring circuit is very stable and absolutely free from any source of offset signals. Also, it has no frequency limitations.

Abstract: A tone predictor may be employed in a modem system to cancel periodic interference components present in a received signal. The tone predictor may be implemented in a receiver arrangement to cancel such periodic interference and to condition a decision error signal utilized to update the adaptive equalizers. The tone predictor may also be implemented in an echo canceler arrangement to cancel such periodic interference and to condition the error signal used to update the echo canceler filter. The tone predictor includes a delay element, configured to decouple the periodic interference component from other noise components, and an adaptive filter structure configured to generate a periodic interference estimate.

Abstract: A preferred timing recovery scheme is particularly suitable for a high speed digital data communication system that employs T-spaced equalization in the receiving device, where echo cancellation occurs after equalization. The timing recovery technique is based upon an analysis of the impulse response of the equalizer structure (e.g., a structure having a feedforward equalizer and a decision feedback equalizer). The filter tap coefficients of the equalizer elements are analyzed and the sampling phase is adjusted such that a cost function associated with the performance of the equalizer structure is substantially optimized. The sampling phase of the receiver is adjusted in response to a control signal generated as a result of the timing recovery techniques.

Abstract: A control system for an AC induction motor, comprising a stator, a rotor, at least two stator windings and rotor windings. The control system comprises a first vector rotator for rotating control signals with a first angle (.alpha.) for providing output signals connected to frequency inverters for providing drive signals to each stator winding of the motor, said first angle (.alpha.) being the time integral of a rotation frequency (w). Moreover, the control system comprises a second vector rotator for counterrotating measured drive voltages and/or currents with a second angle (-.alpha.) which is the inverse of said first angle (.alpha.). The rotation frequency (w) is controlled in dependence of said counterrotated measured voltages and/or currents essentially for maintaining the amplitude of said magnetizing currents (Im) of each stator winding constant which is a necessary condition for obtaining Natural Field Orientation.

Abstract: A method and device for controlling a bridge circuit for providing current or power to a load. The bridge comprises two transistors including flywheel diodes and connected in series between positive and negative power supply rails for conducting current to or from the load under control of a control drive circuit. An LC-circuit is connected between the bridge circuit and the load. The bridge voltage (E) of the connection between the two transistors and the current (I) through the inductance of the LC-circuit are monitored and a firing pulse is supplied to one of the transistors.

Abstract: A method and apparatus for controlling an AC induction motor, having at least two phases. The motor is controlled in a known manner by two input signals S.sub.1, S.sub.2, which are connected to a resolver (1), the output signals of which are used to generate separate supply signals to the motor phases. A measured signal U, representing the rotational speed of the motor, is fed back to the control system and is used for calculating the oscillator frequency of the oscillator (5), which drives the resolver.A calculating circuit calculates the oscillator frequency as the sum of the first control signal S.sub.1 multiplied by a first constant factor, and the tachometer signal U multiplied by a second constant factor.As a result of this control method the oscillator frequency will increase with increasing control signal S.sub.1 and increasing tachometer signal U, but decrease with increasing motor load, because the motor speed will decrease.